Polymerization of gaseous olefins



June 1, 1937.

. N a C) Q, g

x g 1150i? w. E. KUENTZEL ET AL 2,082,454

' 64 Prodzwts Patented June 1, 1937 POLYMERIZATION 0F GASEOUS 0 Ward E.

Ruthruil of Indiana Kuentsel, Whiting, -Iid Robert F. Hammond, Iml, to Standard Oil Company, Chicago,

111., acorporation Application December :8, 934, Serial No. 159,474 '8 Claims. (01. 196-10) Our invention relates to an improved process for the catalytic polymerization of gaseous olefins to low boiling liquid hydrocarbons of the gasoline fling-range.- More specifically we have discovered that while ethylene 'is not acted on by certain of the most advantageous catalysts, which I catalysts will convert propylene or butylene to liquid products substantially-completely and at high conversion rates, if the ethylene is admixed with certain quantities of heavier olefines such as propylene and/or butylene prior to catalytic treatment, the ethylene will be converted to a considerable extent and by recycling .the ethylene fraction the conversion thereof can be carried substantially-to completion; Still heavier olefin material may be used with the ethylene, such as cracked gasoline and unsaturated naphthas.

In a preferred form of our invention, we sub- Ject a mixture of ethylene and propylene, to-

' gether ordinarily with certain quantities of ethane and propane and/oreother inert gases, to eat alytic. treatment. The propylene is practically completely converted to liquids in one pass through the catalyst and the ethylene is partially eliminating a suflicient part ofthe latter to prevent excessive amounts of ethane from building converted. We separate liquid products, eliminatepropane from the system, and recycle a large part of the ethylene-ethane fraction, while up in the system. On the other hand we may operate two successive steps of catalytic treatment adding fresh propylene to the ethylene fraction unconverted .by the'flrst treatment prior to passing it to the second catalytic treatment step.

We have found that there are various catalysts with which our improved process can advantageously be used, particularly catalysts of the aluminum'halide stable double salt type as exemplifiedby' "sodium chloro-a'luminate. Other examples of this class of catalyst are cuprous chloro- 'aluminate,'" calcium ohloro-aiuminate, lithium chloro-aluminate, silver chloro-aluminate, manganese, 'chloro-aluminate, cobalt, chloro-aluminate, mercury bromo-alurrdnate, antimony bromo aluminate, and also double salts of mixed character such as may be formed byaddition of sodium chloride to aluminum'bromide.

As a, specific example of our process, sodium" chloro'aluminate at 350 F. and .750 lbs. per s v but will essentially completely convert propylene in. pressure has essentially no action on ethylene (admixed or not with inert gases such as propane) to liquid products. are necessary to obtain any action on ethylene by itself, and for example even at 650 F. only and Much higher temperatures 3.0% of ethylene is converted to liquid. whereas under these conditions the actionon propylene at thesame timeofcontactissoviolentastocause low yields of desired q d products.

If, however, under the same conditions of 350 F. and 750 lbs. per sq. in. pressure we treat a mixture containing 19.1% ethylene by weight. 20.2% propylene by weight, and the balance propme. using sodium chloro-aluminate as a catalyst, we have found 'an overall conversion toliquids of 59.2% and 62.2% of the total oleflns by w ght.

and analysis of the unconverted gases showed that 35.2% and 31.8% of the cnterlngethylene was converted in the two runs respectively, while 720% and 65.2% of the entering propylene was converted.-..Since theethylcne by iweli would have shown zero conversion under these same conditions, the advantage of our process will be clear.

We may treat ethylene either in the of propylene or butylene or hi her olefins or mixtures thereof as an "activator". Inert gases may,

, of course, be present such as ethane, propane. butane. hydrogen, nitrogen, etc. Weflnd that it is preferable to have at least 50% by w ichtot the "activating higher gaseous *oleflns present,-

based on the amount of ethylene present. in order to obtain the desired The operation of our process will be understood 7 7 description andthe following detailed description 'withreference to from the foregoing general the. drawing attached hereto and which; forms part of this specification and in which:

Figure 1 is a diagrammatic elevational view of suitable apparatus for l 'lgurezisasimilartlcviewofa two-stage system.-

Referring toFlgure 1 ofthe drawing, gasescontaining ethylene together with at least 50% by weight as much propylene and/or butylene, and

ordinarily containing inert gases as well, enter. through line i0 and are pumped by pump ll' through drier chambers i2 and ilwhich are provided with valves ".15, i0, and I1 whereby one chambermay be replaced or recharged without interrupting the operation. The dry gases pass through line i8 to catalyst chamber I! which may be of any convenient type and which may be provided with internal cooling coils 20; "I'he catalyst used is of the aluminum halide stable double salt type as previously described. From chamber iii the product and unconverted gases pass through line 2| andvalve 22 to fractionator 23 from which gasoline and heavier liquid prodcarrying auteur-process,-

are withdrawn b ethylenic gas stream in nets are withdrawn through ofltake 24 while unconverted gases pass overhead through line 25 to iractionator 26. Pump 21 in line 25 may be provided if it is desired to operate fractionator 26 at a higher pressure than fractionator 23. From the bottom of fractionator 26 through valved offtake 28 we withdraw propane, together with any butane not removed with the. gasoline at ofitake 24 from 'fractionator 23, and from the top of fractionator 26 through line 29 we remove a fraction containing any unconverted ethylene which will include 40%-65% of the ethylene originally introduced through line H). We ordinarily recycle at least 50% 01' the gas removed through line 29 to the catalystchamb'er l9 via. valve 30 and pump 3| in line 32. The balance we eliminate through ofltake 33 as fuel gas, in order to prevent ethane from building up excessively in the system.

The ratio between the amount recycled to the amount removed from the system-will depend largely on the ratio of ethylene to ethane in the feed gas in" line H), and. the greater the ratio of ethane to ethylene the greatermust be the ratio of eliminated gas to recycled gas. If there is no ethane in the feed gas in line l0, and no other inert gases which cannot be readily separated from etyhlene by fractionation, we recycle all of the gas from line 29and secure essentially complete ultimate conversion of the ethylene. The greater the ethane content of the original gas, however, the lower the permissible amount of recycling and the'lower the ultimate conversion of the ethylene.

Another modification of our process consistsin operatingin two successive stages on the ethylene fraction. Referring to Figure 2 the feed gas, of the same characteristics as previously described,'enters through line' 34 and is pumped by pump 35 through driers 38 and 31 which, as before described relative to driers l2 and I3 (Figure 1), are provided with valves 38, 39, 40, and 4|. The dried gases or liquefied gases are passed through line 42 to "fractionator 43 where part of the propylene and heavier constituents are withdrawn through the bottom outlet valve 44 while the ethylene fraction plus part of the propylene and heavier oleiins is taken off through top ofitake 45. It has ,been previously stated that we prefer to have-at least 50% by weight of propylene and higher oleflns based on the ethylene in this stream. This ethylene-propylene mixture in 45 is passed through condenser 48 and pump 41 into catalyst chamber 48 which as previously described may beof any convenient type and which may be provided with internal cooling means 49. Liquid products and unconverted gases are drawn oil? from chamber 48 through ofitake line 50 and valve 5| and are passed into fractionator 52, wherein liquid products plus propane and butane the bottom ofitake 53 while ethylene unconver ed in catalyst chamber 48, together with any ethane and other inert gases, is drawn off through line 54 and passed by pump 55 to catalyst chamber 56 which also may be" provided with suitable internal cooling means 51. Prior to entering catalyst chamber 55 the propane-propylene stream from fractionator 43 via valve 44, line pylene (based on the ethylene) is restored prior to the entrance to catalyst chamber 56.

Following the second catalytic treatment in chamber 56 the gases and products are withdrawn products are removed line 54 is joined by the.

58 and pump 59, whereby the aforedescribed desired minimum amount of prothrough valve 60 in line GI and pass to fractionator 62 from which unconverted gases are eliminated through v alved ofltake 53 while liquid through valved offtake 64.

It will be understood that the apparatus as described in the foregoing will be supplemented by various auxiliary devices in practice. Forexample, the fractionators 23, 25, 43, 52, and 62 will be provided with suitable bottom heating means and top cooling means, controls, etc. whereby proper operation is insured. Suitable preheaters ahead of the catalyst chambers I9, 48, and

56 may be used, and/or heatinterchangers may be used for such purpose, or the incoming'gases .may be passed through the internal cooling means We prefer to utilize as feed gas for our. process a gas containing from 15% to of olefins by volume. The desired ratio of propylene and/or heavier olefins to ethylene has been previously stated to be (minimum) 50% by weight of the ethylene. The catalysts of the preferred aluminum halide stable double salt type have been previously described. Our operating conditions for the catalytic conversion in the catalyst chambers I9, 48, and 55 may be in the range of temperatures of 150-'750 F., pressures of 200-3000 lbs. per sq. in. and flow rates of 400-24900 cu. ft. of free entering gas (measured at 60 F. and atmospheric pressure) per cu. ft. of free catalyst volume per hour. Generally speaking, the rate of flow is proportional to the pressure, i. e. if with a given catalyst, temperature, and feed gaswe use a flow rate 017.8000 cu. ft./cu. ft./hr. at 200 lbs. per sq. in. pressure, we .use a flow of 24,000 cu. ft./cu. ft.'/hr. with a pressure of 600lbs. per sq. in., so that the time-of contact with the catalyst remains approximately constant. Ordinarily.

however, we prefer to operate on the range of 300-450" F. temperature, 500-1000 lbs. per sq. in. pressure, and rates of 2000-6000 cu.- ft. of free entering gas per cu. ft. of free catalyst volume per hour. I

The foregoing being a full and complete description of our invention, it is'understood that we are not limited therein except as expressed in the claims as follows:

We claim: j

1. The process of obtaining liquid products from a gas mixture containing ethylene together with higher gaseous oleflns which comprises separating a part of the higher gaseous oleilns to leave in the remaining gas at least 50% of higher gaseous olefins by weight of the ethylene,

subjecting said remaining gas to catalytic polystep.

2. In a process for polymerizing a gas mixture containing ethylene to liquid hydrocarbons, the

steps comprising polymerizing ethylene in the presence-of at least 50% of its-weight of higher normally gaseous olefins with a catalyst compris-' ing an aluminum halide stable double salt, at a temperature within the range of 300 to 750 F.

and under a pressure within the range of 200 to 3000 lbs. per square inch, and separating poly- 'merized hydrocarbon liquids from unconverted gases.

3. -In a process for polymerizing a gas mixture containing ethylene to liquid hydrocarbons, the

steps comprising polymerizing ethylene in the presence of at least 50% of its weight of higher normally gaseous olefins with a catalyst comprising an aluminum halide stable double salt, at a temperature of 300 to 450 F., under a pressure within the range 01" 500 to 3000 lbs. per square inch, and at flow rates 'of 2000 to 6000 cubic feet free entering gas per cubic feet of free catalyst volume per hour. v

4. In a process for polymerizing a gas mixture containing ethylene to liquid hydrocarbons, the

steps comprising polymerizing ethylene in the presence of at least 50% of its weight of higher normally gaseous olefins with a catalyst comprising an aluminum chloride stable double salt,

at a temperature within the range of 300 to 750 F. and under a pressure within the range of 200 to 3000 lbs. per square inch, and separating poly- 'merized hydrocarbon liquids from unconverted gases. 7

5. In a process for polymerizing a gas mixture containing ethylene to liquid hydrocarbons, the

. steps comprising polymerizing ethylene in the presence of at-least 50% of its weight of higher normally gaseous oleiins with a catalyst comprising lithium chloro-aluminate at a temperature within the range of 300 to 750 F. and under a pressure within the range of 200 to 3000 lbs. per square inch, and separating polymerized hydrocarbon liquids from unconverted gases.

7. In a process for polymerizing a gas mixture containing ethylene to liquid hydrocarbons, the steps comprising polymerizing ethylene in the presence of at least 50% of its weight of higher normally gaseous olefins with a catalyst comprising magnesium chloro-aluminate atatemperature within the range of 300 to 750 F. and under a pressure within the range of 200 to 3000 lbs. per square inch, and separating polymerized hydrocarbon liquids from unconverted gases.

8. In a process for polymerizing a gas mixture containing ethylene to liquid hydrocarbons, the steps comprising polymerizing ethylene in the presence of at least 50% of its weight of higher normally gaseous oieflns with a. catalyst comprising sodium chloro-aluminate, at a temperature within the range of 300 to 750 F. and under a pressure within the range of 200. to 3000 lbs. per square inch, separating polymerized hydrocarbon liquids from unconverted gases, separating from the unconverted gases a fraction containing ethylene and recycling said fraction to the catalytic polymerization step.

WARD E. KUEN'IZ'EL. ROBERT F. RUTHRUFF. 

